Central Nervous System Flashcards
(180 cards)
1
Q
What is the difference between the CNS and PNS?
A
CNS is composed of the brain and spinal cord; PNS consists of nerves that connect the CNS to peripheral structures
2
Q
Describe Neurons
A
Functional units of the nervous system which generates electrical signals (action potentials)
3
Q
Describe Glial cells
A
Non-neuronal cells that support neurons generate nerve impulses (they do not themselves)
4
Q
Where are interneurons found?
A
Entirely in the CNS
4
Q
What type of neuron accounts for >99% of total neurons?
A
Interneurons; the neurons that connect the afferent and efferent
5
Q
What are the four types of glial cells in the CNS?
A
- Astrocytes
- Oligodendrocytes
- Ependymal cells
- Microglia
6
Q
What participates in the formation of myelin sheaths for the axons in the CNS?
A
Oligodenodrocytes
7
Q
What are the three types of glial cells in the PNS?
A
- Schwann cells
- Satellite cells
- Enteric glia
8
Q
What participates in the formation of myelin sheaths for the axons in the PNS?
A
Schwann cells
9
Q
Where is the frontal lobe found?
A
Where the forehead is
10
Q
Where is the parietal lobe found?
A
Behind the frontal lobe, on the upper half of the brain
11
Q
Where is the temporal lobe found?
A
Below the frontal and parietal lobes; the lower half of the brain
12
Q
Where is the occipital lobe found?
A
Lower, back portion of the brain; behind the temporal and (also below) the parietal
13
Q
Where is the cerebellum?
A
Below the temporal and occiptal lobes; in the base of the skull
14
Q
Where is the medulla oblongata?
A
Long structure in front of the Cerebellum and below the Pons and Temporal Lobe
15
Q
Where is the Pons?
A
Between the Temporal Lobe, Cerebellum, and the Medulla Oblongata
16
Q
What is the coronal plane?
A
Splitting the brain into a back and front
17
Q
What is the Horizontal plane?
A
Splitting the brain into a top and bottom
18
Q
What is the sagittal plane?
A
Splitting the brain into a left and right
19
Q
What is the difference between the anterior and posterior?
A
Anterior is the front, posterior is the back
20
Q
What is the difference between rostral and caudal?
A
Rostral is towards the head (longitudinal axis of the forebrain), Caudal is towards the tail (longitudinal axis of the brainstem and spinal cord)
21
Q
What is the difference between dorsal and ventral?
A
Dorsal is the top, ventral is the bottom
22
Q
What structures are found in the sagittal section of the forebrain?
A
- Cerebrum
- Diencephalon
23
Q
What structures are found in the sagittal section of the midbrain?
A
- Midbrain
24
What structures are found in the sagittal section of the hindbrain?
* Cerebellum
* Pons
* Medulla Oblongata
25
What is the difference between the forebrain, midbrain, and the hindbrain?
26
What structures are found within the diencephalon?
* Thalamus
* Pineal gland
* Hypothalamus
* Pituitary gland
27
What is the function of the thalamus?
Integrating center and relay station for sensory and motor information
28
What is the function of the pineal gland?
Melatonin secretion
29
What are the functions of the hypothalamus?
* Homeostasis
* Behavioral drives
30
What is the function of the pituitary gland?
Hormone secretion
31
What are the structures within the brain stem?
* Thalamus
* Optic nerve
* Midbrain
* Pons
* Medulla oblongata
* Reticular formation
32
Where is the thalamus found?
On top of the midbrain
33
What is the function of the midbrain?
Eye movement
34
What are the functions of the Pons?
* Relay station between cerebrum and cerebellum
* Coordination of breathing
35
What is the function of the medulla oblongata?
Control of involuntary functions
36
What are the functions of the reticular formation?
* Arousal
* Sleep
* Muscle tone
* Pain modulation
37
What is gray matter composed of?
Cell bodies (which gives the area a gray appearance)
38
Why is grey matter grey?
It lacks relatively few myelinated axons, whereas white matter has more myelinated axons
39
What is white matter composed of?
Tracts of myelinated axons
40
What are the structures (9) of the limbic system?
* Thalamus
* Pineal gland
* Hippocampus
* Cerebellum
* Amygdala
* Pituitary gland
* Hypothalamus
* Cerebrum
* Basal ganglia
41
What are the structures of the limbic system associated with?
* Learning/memory
* Emotion
* Visceral function (Appetite)
* Sex
* Endocrine function
42
What is the function of the cerebral cortex?
Participates in perception, generation of skilled movements, and cognitive functions (reasoning, learning, and memory)
43
What is the function of the basal ganglia?
Participate in the initiation of movement and coordination of skeletal muscle activity
44
What are the functiosn of the thalamus?
Acts as a synaptic relay station for sensory pathways on their way to the cerebral cortex; also participates in control of skeletal muscle coordination, and has a key function in awareness
45
What are the functions of the hypothalamus?
* HOMEOSTASIS
* Participate in temperature control, water balance, eating and drinking behavior, and emotional behavior, also regulates the reproductive system and circadian rhythms
46
What are the functions of the cerebellum?
Coordinates movements, such as eye movement and those for posture and balance. Participates in some forms of learning.
47
What are the functions of the brain stem (4)?
1. Cardiovascular, respiratory, disgestive control
2. Sleep/wake cycle, arousal
3. Balance and posture
4. Locomotor initiating centre
48
What are the functions of the spinal cord?
Locomotor pattern generator (producing rhythmic movements), spinal reflexes
49
What are the four protective elements associated with the CNS?
1. Bone
2. Meninges
3. Cerebrospinal fluid (CSF)
4. Blood-Brain Barrier (BBB)
50
Which bones are protectice elements with the CNS?
* Skull for the brain
* Vertebrae for the spinal cord
51
What are the layers of the meninges?
* Dura Mater
* Arachnoid mater
* Pia mater
52
How does the CSF protect the CNS?
It cushions the structures (between the skull/meninges, and the brain)
53
How does the BBB protect the CNS?
Helps maintain a stable environment for the brain; it controls the types of substances that enter the brain extracellular fluid and the rates at which they enter
54
# Define
CSF
Cerebrospinal fluid
55
# Define
BBB
Blood-Brain Barrier
56
How many spinal nerves convey signals to and from the spinal cord?
31
57
What is the breakdown of the 31 spinal nerves?
* 8 cervical
* 12 thoracic
* 5 lumbar
* 5 sacral
* 1 coccygeal
58
In what order are the sections of the spine?
Cervical to thoracic to lumbar to sacrum to coccyx (tailbone)
59
# Define
Dermatome
areas of skin on your body that rely on specific nerve connections on your spine
60
# Define
Myotome
areas of muscles in your body that rely on specific nerve connections on your spine
61
What dermatomes are the cervical vertebraes responsible for?
Head, neck, shoulders, arm, hand
62
What dermatomes are the thoracic vertebraes responsible for?
Trunk
63
What dermatomes are the lumbar vertebraes responsible for?
Waist, front of legs, feet
64
What dermatomes are the sacral vertebraes and coccygeal responsible for?
Buttocks, genitals, anus, back of legs, feet
65
How are vertebraes named?
Letter for their second and number for descending order
## Footnote
ex. C5; the 5th vertebrae in the cervical section of the spine
66
What does the dorsal root do?
Send sen**s**ory information from the body to the brain
67
What does the ventral root do?
Send mo**t**or commands from the brain to the body
68
What are the functions of the spinal cord?
* Send info from the body to the brain (dorsal root)
* Send commands from brain to the body
* Coordinate reflexes (acting without signals from the brain)
* Contains central pattern generators that control rhytmic movements (walking, flying, swallowing etc.)
69
How do afferent neuron axons enter the spinal cord?
Enter on the dorsal side of the cord via the dorsal roots
70
Where are the cell bodies of the afferent neurons?
In the dorsal root ganglia
71
How do efferent neuron axons exit the spinal cord?
They leave through the spinal cord on the ventral side via the ventral roots
72
What is a spinal reflex?
Where the spinal cord initiates a response without input from the brain
73
What is the detailed explanation for where information goes in a spinal reflex?
Sensory information enters the spinal cord and it acts without input from the brain. However, sensory information about the stimulus may be sent to the brain.
74
What is the path in a spinal reflex?
A stimulus occurs, which is translated into sensory information. This info travels via an interneuron to the integrating center which sends a command to muscles or glands, which results in a response.
75
How do spinal cord injuries work, in terms of what control/functions are lost?
When spinal cord is damaged at a given level, sensation from and the motor control of functions **below** that level are likely to be **abnormal**.
76
What is Brown-Sequard Syndrome?
An injury in one side of the spinal cord (left or right)
77
What are the three specializations of the brain from a functional viewpoint?
1. Sensory areas
2. Motor areas
3. Association areas (integrate information from sensory and motor areas)
78
What are the association areas of the brain (5)?
1. Motor association area
2. Sensory association area
3. Visual association area
4. Auditory association area
5. Prefrontal association area
79
How does sensory information travels to the brain?
* From the body to the brain: along ascending pathways in the spinal cord
* From head to the brain: via cranial nerves
80
What sensory information does not reach the brain?
* Visceral reflexes are integrated in brainstem or spin cord
They usually do not reach concious perception (e.g., control of blood pressure)
81
What happens to sensory information after going to the primary receiving areas?
It continues to association areas for futher complex processing/integration
82
What sensory pathway does not synpase in the thalamus?
Olfactory; it first goes to the olfactory bulb
83
What are ascending pathways?
* Also called afferent pathways
* send somatosensory information from the body up to the brain through a series of afferent nerves
84
What are somatic senses?
senses that have to do with the experience of touch
85
What are somatosensory pathways?
Pathways that relay information between the brain and nerves in the skin and organs
86
What are the example of the somatic senses?
1. Touch
2. Proprioception/Kinesthesia
3. Temperature
4. Nociception (pain/itch)
87
How do pain, temperature, and coarse touch go through the ascending pathway?
1. Cross the midline in the spinal cord
2. Sensory pathways synapse in the thalamus
88
How does fine touch, vibration, and proprioception go through the ascending pathway?
1. Crosses the midline in the medulla
2. Sensory pathways synpase in the thalamus
89
Where do the neurons in the descending pathways come from?
* The primary motor cortex
* Premotor area
90
What are corticospinal/pyramidal pathways?
* Pathways that control rapid, fine movements of the distal extremities
* Originate in the cerebral cortex
91
What are the brainstem/extrapyramidal system pathways?
* Involved with coordination of the large muscle groups of the trunk and proximal portions of limbs
* Originates in the brainstem
92
Where do ascending, sensory nerves cross the midline?
The spinal cord and the medulla
93
What are seven classes or neurotransmitters or neuromodulators?
1. Acetylcholin (ACh)
2. Biogenic amines
3. Amino acids
4. Neuropeptides
5. Gases
6. Purines
7. Lipids
94
What is the difference between neurotransmitters and meuromodulators?
* **Neurotransmitters**: for "rapid" communication
* **Neuromodulators**: for "slower" events like learning, can occur over minutes/hours/days, can modify the response to specific neurotransmitters
95
Which neurons release acetylcholine?
Cholinergic neurons
96
What are the two receptors for acetylcholine?
* Muscarinic (G protein coupled)
* Nicotinic (ligand-gated ion channels)
97
What are muscarinic receptors associated with?
Higher cognitive processes like learning and **m**emory
98
What are nicotinic receptors associated with?
Rewards pathways (**nicotin**e/tobacco addiction)
99
What is the difference in speed between nicotinic and muscarininc receptors?
* Nic**t**onic: Fas**t** EPSP
* Muscarinic: Slow EPSP
100
What are biogenic amines?
* Small molecules synthesized from amino acids
* Includes some of the most common neurotrasmitters
101
What are examples of biogenic amines?
* Dopamine
* Norepinephrine
* Serotonin
* Epinephrine (not common in CNS)
102
Why is norepinephrine important in CNS?
It relates to alterness, attention, cognitive function, and stress reactions such as anxiety
103
What receptors does norepinephrine use?
Adrenergic receptors (Alpha and Beta)
104
Do biogenic amines have an excitatory or inhibitory effect?
Both!
105
What is the function of serotonin?
Regulates food intake, reproductive behaviour, and emotions (mood, anxiety)
106
Why is serotonin an important biogenic amine?
* It is a neuromodulator at every structure in the brain and spinal cord
* It has 16 different receptor subtypes (G-protein and ligand gated)
107
Why are amino acid neurotransmitters most common in the CNS?
They can affect all neurons
108
What are common amino acid neurotransmitters?
* Glutamate (excitatory)
* Glycine and GABA (inhibitory)
109
What is the major excitatory neurotransmitter in the CNS?
Glutamate; it accounts for 50% of excitatory synpases in the CNS
110
What is the major inhibitory transmitters in the brain?
GABA
111
How does alcohol interact with glutamate and GABA?
* Stimulates GABA synapses
* Inhibits glutamate synapses
* This causes depression of brain electrical activity
112
# Define
Learning
Acquisition of information as a consequence of experience
113
# Define
Memory
Relatively permanent storage of learned information (ability to retain and recall information)
114
What is the difference between declarative (explicit) and procedural (implicit) memory?
* Declarative: retention and recall of experiences that can be put into words
* *Example is a wedding; when, where it occured*
* Procedural: memory for skilled behaviours independent of any conscious understanding
* *Example is riding a bike, or a fear of spiders*
115
What type of memory requires conscious attention?
Declarative
116
What areas of the brain are involved in declarative memory?
* Hippocampus
* Amygdala
* Other parts of the limbic system
117
What areas of the brain are involved in procedural memory?
* Sensorimotor cortex
* Basal nuclei
* Cerebellum
118
What is short-term (working) memory?
Memories that last seconds to minutes, and are suscpetible to external interference
119
What are long-term memories?
Memories that last days to years, and can survive disruptions
120
What is the transition from short-term to long-term memory called?
Consolidation
121
What is the loss of memory called?
Amnesia
122
What is the impaired retrieval of old memories called?
Retrograde (short-term) amensia
123
What is the impaired formation of new memories called?
Anterograde amensia
124
What is the cause of anterograde amnesia?
Damage to the limbic system and associated structures, like the hippocampus, thalamus, and hypothalamus
125
What is long-term potentiation?
* a process involving persistent strengthening of synapses that leads to a long-lasting increase in signal transmission between neurons
* Relates to synaptic plasticity
126
What does a potentiated synapse look like?
127
What are examples of long-term potentiation (LTP)?
The cooprative activity of AMPA and NMDA receptors; as you potentiate, more AMPA synapses are added, increasing sensitivity to glutamate
128
What portion of the brain produces and comprehends language?
The left hemisphere
129
# [](http://)
What does it mean to produce and comprehend language?
A person is able to:
* Conceptualize the words (to say or write)
* Neural control of the act of speaking or writing
* Recent verbal memory
130
How do males and females process language differently?
* Males: Use mainly the left hemisphere
* Females: Both hemispheres are used for some language task
131
What is the role of Wernicke's area?
Understanding language/comprehension
132
What is the role of Broca's area?
Producing speech/expression
133
What is the path of speaking a written word?
134
What is the path of speaking a heard word?
135
What does damage to Wernicke's area cause?
* Receptive aphasia
* Unable to understand sensory input
136
What does damage to Broca's area cause?
* Expressive aphasia
* Unable to understand complicated sentences with multiple elements
* Difficulty speaking or writing normal syntax
137
What is global aphasia?
A mix of receptive and expressive aphasia; inability to understand, and produce language
138
What is electroencephalogram (EEG)?
* A measurement of electrical activities in the brain using electrodes attached to the scalp
* Used as a diagnostic tool
139
What is the difference in EEG pattern between someone alert and someone drowsy?
140
What are the two phases of sleep?
* NREM (non-rapid eye movement) - N1, N2, N3
* REM (Rapid eye movement)
141
What are the three stages of NREM sleep?
1. N1: theta waves begin to intersperse among alpha pattern (light sleep)
2. N2: theta waves, sleep spindles and K complezes
3. N3: delta waves (slow-wave or deep sleep)
142
How long does the progression of NREM sleep take?
30 to 45 minutes
143
What is paradoxical sleep?
* REM sleep
* The asleep is difficult to arouse but there is intense EEG activity similar to that of the alert/awake state
144
When does REM begin and how long do the episodes last?
* Onset is 50 to 90 minutes
* First episode is 10 minutes, and gets progressively longer
145
What is the pattern of uniterrupted sleep?
N1 to N2 to N3 to N2 to an episode of REM
146
Why do we need sleep?
* It is a homeostatic requirement!
* During sleep, the brain experiences reactivation of neural pathways stimulated during the prior awake state
147
What are the effects of sleep deprivation (3)?
* Impairs the immune system
* Causes cognitive and memory deficits
* Leads to psychosis and even death
148
During what stage of sleep does dreaming occur?
REM
149
# Define
Motivation
Internal signals that shape voluntary behaviours which lead to hromonal autonomic, and behavoural responses
150
# Define
Emotion
Results from the relationship between an individual and the environment
151
What is primary motivated behaviour?
Behaviour directly related to hemostatsis like drinking water, eating, maintaining body temperature
152
What is secondary motivated behaviour?
Behaviours related to pleasure or addictive behaviours like over-eating, taking recreational drugs
153
What two things are insperable from motivation?
* Reward
* Punishment
154
What is the reticular activating system (RAS)?
a bundle of nerves that sits in your brainstem whose job is to regulate behavioural arousal, consciousness and motivation
155
What pathways are a part of the RAS?
* Mesolimbic dopamine
* Mesocortical dopamine
156
Where does the RAS begin, and what does it do in the brain?
It begins in the midbrain, and releases dopamine in areas that process emotion
157
How are the forebrain structures involved in relation to emotional responses?
| What behaviours are associated with the forebrain structures
Modulation, direction, understanding, or even inhibtion of emotional behaviours
158
How are the limbic areas involved in relation to emotional responses?
| What responses are associated with the limbic areas?
Inner emotions like fear
159
How is the lateral hypothalamus involved in relation to emotional responses?
| What responses are associated with the lateral hypothalamus?
Rage responses
160
What are dementias?
Neurodegenerative disorders with decline in memory and other cognitive skills that reduce a person's ability to perform everyday activities
161
What is Alzheimer's Disease (AD)?
* Most common cause of demetia
* Slowly progressive, characterized by neuritic plaques and neurofibrillary tangles in medial temporal lobe and cortical structure
162
What are the components of AD? (3)
* Senile plaques
* Neurofibrillary tangles
* Synaptic loss
163
What are the risk factors of AD?
* Age (65 or older)
* Genetic (70% of cases)
* Sex (females)
* Lifestyle
* Medical factors (CVD, obesity, diabetes)
* Air pollutants, metals, and infections
164
What is Parkinson's Disease (PD)?
* A degenerative, progressive disorder affecting neurons in substantia nigra pars compacta (SNpc) of basal ganglia
* Degeneration in dopeminergic neurons which control body movement
165
When does symptoms of PD appear?
After the loss of 60-70% of dopaminergic cells in SNpc, usually over 5-10 years
166
What are the symptoms of PD?
167
What are the treatments for PD? (2)
* **Increase of dopamine in substantia nigra** (L-Dopa, a precursor to dopamine is used)
* **Deep brain stimulation** (stimulating different regions of the basal ganglia which reduces symptoms)
168
What is ALS?
A progressive neurodegenerative disease of the upper and lower motor neurons (cortical and spinal motor neurons)
* Involves the degeneration of axons within the anterior and lateral corticospinal tracts
169
What % of ALS cases are genetic?
5-10%; most cases are sporadic
170
When is the first onset of ALS?
Usually between ages 50 and 65
171
What are the common symptoms of ALS?
* Muscle weakness, twitching, cramping
* Slurred speech
* Trouble swallowing
* Eventual impairement of muscles
172
What is the possible molecular mechanism of ALS?
Excitotoxicity, the ability of glutamate or related excitatory amino acids to mediate the death of central neurons under certain conditions
173
What is Multiple sclerosis? (MS)?
An autoimmune disease of the CNS charcetrized by:
* Chronic inflammation
* Demyelination and axonal damage
* Astroglial proliferation (larger glial cells being produced)
* Neuronal loss
174
Which sex is more affected by MS?
Females
175
What are the subtypes of MS? (4)
* Relapsing-remitting MS (RRMS)
* Secondary-progressive MS (SPMS)
* Primary-progressive MS (PPMS)
* Progressive-relapsing MS (PRMS)
176
What are the risk factors for developing MS?
* Environmental factors (highest in North America, lowest around the equator)
* Genetic and Racial associations (35-75% inherited, Caucasian and African American at highest risk)
* Infections
* Diet (high in animal fat)
* Toxins
177
What type of waves are associated with N1?
Theta waves that intersperse among alpha pattern
178
What type of waves are associated with N2
Theta wave, sleep spindles, and K complexes
179
What type of waves are associated with N3?
Delta waves
